Development of a Wearable Human Pulse Measuring Device using Piezoelectric Sensor

Pulse diagnosis, an ancient technique in traditional Chinese medicine (TCM), is an effective non-invasive method for diagnosing human diseases. Traditionally, the practitioners use their fingertips to sense the pulse of the blood vessels on the patient’s wrist. However, this method heavily and subjectively depends on the doctor’s experience. Additionally, it’s impossible to store the patient’s pulse records for posterior review or analysis. To solve such restrictions, a wearable device that could precisely measure the wrist-based pulse signal and save it as digital data was proposed. In the proposed device, a piezoelectric sensor, which is a highly sensitive, lightweight, stable sensor, was used to record variations of the pulse. Since wrist pulse signals collected by the device contain various types of noises which make it difficult to assess the shape of the pulse wave, a slight low-pass filter was applied to remove high-frequency noises. The processed data was then compared with simultaneous electrocardiogram (ECG) data for the sake of evaluation. The preliminary results showed that recorded data from the proposed device is consistent with the equivalent ECG data.